City agencies should do monthly sweeps of public housing to ferret out sex offenders living under the radar and notify residents when they evict one, advocates and a Queens councilman said yesterday.

They spoke at a press conference at City Hall called after yesterday’s Post revealed that over 200 registered sex offenders were illegally living in public housing units – giving them easy access to kids and vulnerable families.

Councilman Eric Gioia (D-Queens) was among those complaining that the New York City Housing Authority and the NYPD were not doing enough to keep sex offenders out, as per federal law.

“The NYPD provides numbers [of them living illegally in public housing] every six months to the [NYCHA],” Gioia said. “This is not enough. It should be done every single month, if not every single week.”

Karen Dennis, who chairs the Neighborhood Advisory Board in Queens, said, “You’re walking the streets with these people. They’re looking you in the face, and you do not know whether they’re going to do something to you or not because you do not know who they are.”

A registered sex offender recently tried to rape an elderly woman in the Ravenswood Houses in Long Island City, Queens.

The NYCHA said it “strongly enforces tenancy proceedings against anyone who presents a danger to the health and safety of residents in public housing” and that eviction proceedings “are initiated immediately.”